Many activities require eye protection due to the presence or creation of harmful visible, ultraviolet, and infrared light. One example of such an activity is welding where intense light is generated by the welder's torch and the heated metal. Current safety standards for industrial eye and face protection for welding and other activities are published by the American National Standards Institute, Inc. (ANSI) in American National Standard Practice for Occupational and Educational Eye and Face Protection, ANSI Z87-1-1989, incorporated herein by reference.
The ANSI standards define a set of shade ratings between 1 and 14 based on the weighted transmittance of luminous (380-780 nm), far ultraviolet (200-315 nm), near ultraviolet (315-385 nm), infrared (780-2000 nm), and blue (400-1400 nm) light. The ANSI standards also indicate the minimum shade protection recommended for certain specific activities. For electric arc welding, a protective lens should have a shade rating of 10-14, for gas welding, shades 4-8 are recommended, and for cutting or torch brazing, shades 3-6 are recommended.
In meeting these standards, those engaged in these hazardous light-generating activities must often wear eye protection devices which are extremely limiting and usually dedicated to that particular activity. For example, a welder typically has a special helmet, mask, or pair of goggles that is worn only while welding. Furthermore, such a helmet, mask, or goggles often provides only a limited range of vision as the protective lenses of the eye protection device have only a small viewing area.
These features of current eye protection devices are inconvenient for many wearers. For example, a worker on a job such as bridge repair, where welding is only one of the necessary activities, would find it convenient to have an eye protection device that could be used for both welding and other activities. Unfortunately, the lens shades required for eye protection devices appropriate for welding are usually too dark for other activities. Thus, there is a need for an eye protection device that can be used with activities that generate harmful light irradiation and can still be used with other activities that do not require such extreme light shielding.
In addition, workers must often wear other protective gear such as respirators which may not be conveniently or cost-effectively combined with current protective helmets, masks, or goggles. There is a need for a lightweight, low-cost light filtering device that can be used in conjunction with other protective gear without requiring that such gear be dedicated for use only with harmful light-generating activities.
The light filtering lens films of the present invention address these needs. The lens films of the present invention can be mounted on the lens or lenses of existing eye protection devices and are often detachable from these physical eye protection devices so that a worker can continue to wear the physical eye protection device while engaged in other activities. The lens films of the present invention provide a convenient, lightweight, low cost product for protecting wearers from harmful light arising from a wide variety of sources.